You can install metal valley flashing but it is common to.
How to install mineral surfaced rolled roofing.
Apply the first course with a full width strip of roll roofing so that its lower edge.
It was pretty easy to install and took about an hour to do by myself including setup and tear.
Enlist the help of one or two helpers to handle the long strips.
Use 1 inch nails for new roofing.
They are long enough to penetrate the sheathing.
Valleys will be open so flash them before hand with metal or two layers of roll roofing the first an 18 inch wide strip and the second 36 inches wide.
Place the first layer of rolled roofing on the roof.
How to do it.
Install drip edge flashings roofing felt and wsu if needed.
Fasten the strips with rows of nails located 1 and 8 from the roof edge and spaced 4 on center in each row.
Bought this roll from home depot.
The first row of roofing material is then rolled out and aligned with the chalk line.
It is secured to the substrate by driving roofing nails 3 4 inch from the edges spaced every three inches.
Place 9 wide strips of roll roofing along the eaves and rakes positioning them to overhang the deck to 3 8.
This is not a how to video.
Use 1 nails for re roofing.